Stapling machine



June 3, 1947. L. OBSTFELD I STAPLING MACHINE Original Filed Jan. 2, 1941Fig-1&

INVENTOR LOU OBST F E LD BY f ATTORNEY Patented June 3, 1947 ZAZigiZtSTAPLING MACHINE Lou Gbstfeld, Brooklyn, N. Y., assignor of onehalf toAbraham I. Obstfeld, New York, N. Y.

Original application January 2, 1941, Serial No.

372,699. Divided and this application November 3, 1942, Serial No.464,365

7 Claims.

This invention relates to the art of stapling, and more particularly toan improved stapling machine and an improved staple for use with thesame.

The primary object of my invention is to generally improve the art ofstapling, and more especially stapling machines and thin wire staplessuch as are usually cemented together to form a stick.

A more specific object is to avoid jamming of staples in the staplemagazine. Such a jam prevents further feed of staples by the staple feedspring, thus rendering the machine inoperative. In most machines themagazine is inaccessible except at one end for loading, and it istherefore a very difficult matter to free a, jammed magazine. Afterconsiderable study of this problem, I have come to the conclusion thatthese staple jams are caused by rotation of a free staple about its topor bridge until the legs point toward the legs of next adjacent staples,alongside of which they then become wedged. The troublesome staple maybecome free in the first instance due to loading of a staple stickagainst an unfinished staple stick, or due to breakage of a staple stickduring loading or during violent rapid operation of the staplingmachine. In most cases a loose staple is fed along with the otherswithout difficulty, but in rare instances such a staple may swingupwardly about its bridge to a nearly horizontal position, and thus leadto a staple jam. One primary object of the present invention is toovercome this diflicultyand to prevent jams of this character.

The: difficulty might be overcome by using a very small tolerance orclose fit of the staple magazine about the staples, but this wouldgreatly increase the manufacturing expense. Moreover, the trend indesign is to make these stapling machines out of heavy gauge sheetmetal, but then it is practically impossible to provide a magazinepassage having very small tolerance, as there is always a certain amountof spring or opening up of the material after it leaves the formingdies. There are also irregularities in the thickness of the metal.

Accordingly, an important object of the present invention is toeliminate staple jams, without, however, in any way reducing thetolerance or clearance between the staples and the staple magazine, andWhile making the magazine out of bent heavy gauge sheet metal parts.

This application is a division of my application Serial No. 372,699,filed January 2, 1941, now Patent No. 2,321,847, patented June 15, 1943.

such other objects as will hereinafter appear, my invention consists inthe staple and machine elements and their relation one to the other,-ashereinafter are more particularly described in the specification andsought to be defined in the claims. The specification is accompanied bydrawings, in which:

Fig. l is a partially sectioned side elevation of a stapling machineembodying features of my in vention;

Fig. 2 is a partially sectioned side elevation of a fragment of themagazine, and is explanatory of the invention;

Fig. 3 is a similar view showing a loose staple being returned to properposition;

Fig. 4 is a similar view of a .prior art machine showing a loose stapleturned to nearly horizontal position;

Fig. 5 is a similar view showing how sucha staple may lead to a staplejam;

Fig. 6 is an enlarged fragmentary transverse section explanatory of myinvention;

Fig. 7 is a fragmentary section taken in the plane of the line 1-1 ofFig. 6;

Fig. 8 is a transverse section through a staple magazine loaded with myimproved staples; v

Fig. 9 is a transverse section through a stapling machine and clinchinganvil at the staple driving blade; r

Fig. 10 is a similar section, but with the anvil moved for temporaryfastening;

Fig. 11 is a view similar to Fig. 10, but showing the temporary fastenedstaple;

Fig. 12 is a section through a machine having a modified drive channel;7

Fig. 13 is a similar view illustrating the operation of the modifieddrive channel; and

Fig. 14 is a section explanatory of an advantage of the modified machineand of my improved staple when used as a tacker.

Referring to the drawing, and more particularly to Fig. 1, I there showa desk stapling machine of a known type, said machine comprising a baseI2 carrying a clinching anvil M. A stapling arm generally designated I6is pivotally mounted on base l2. It comprises a, staple magazine l8through which staples are fed forwardly by means of a feed spring (notshown) toward a staple driving blade 20, the latter being operated byasuitable plunger 22.

Referring now to Fig. 4 of the drawing, staples 24 are carried on astaple core 26 and are confined thereon by a. surrounding staplemagazine wall 28. For any of a number of reasons, the

the staples, attempt to force these pieces one after In prevalentpractice another into-the machine. the machines are of the front-loadingtype w1th a safety pawl, such as is indicated at 80 in Fig. 1',

and the staples are forced into the front end of the machine against theaction of the staple pusher and staple feed spring. Thus the legs maybecome turned and overlapped in condition for a jam, or may even bejammed duringthe loadfest itself when the feed spring attempts to pushthe staples in the opposite direction, with the turned staple movingpoint first.

' Howeven the. difficulty. is-not caused solelyrby loading. but may:arise duringviolent operation ofthemachin'e; asin-f'actories usingthemachine for rapid production purposes. When the staples insthemachine have: been-nearly. usedup; .the resulting extension of-.-the.feed springi greatly-re.- duces the feedaspring pressure, and. at" this.time the vibration or pounding on the. machine-may afford sufficientseparation toipermit a staple. to

rotate;: V J

On some occasions a loose staple may swing upwardly over a large angle;.as-indicated inv Fig. 4: In such case;,the:ends;of the loosestaple 30may move alongside of the staples andsob'ecome wedged betweenathestaplesand the magazine walls. This-produces ajam whichw-ill-prevent: furtherfeed of'staples,;and mayproveextremelydifiicult to relieve. I

The critical angle, theoretically, is 45. A'sta pleat-a less angle willbe-restored to normal position. A staple at a greater anglemaybejammed.

An ordinary. staple'compriseslegs, disposedperpendicularly to aconnecting top-:orqbridge; In accordance 'withthe .present invention,this staple construction is modified by-sloping.2a.leg. of the staple.This. is indicated; at 32 in Fig. 8. The other leg 34 may. also:besloped outwardly. but, .I find it better to: leave: thisleg.perpendicular to the, bridge 36; Thestaple magazine. of my; in-iv provedmachine is made to fit the sloped le jsta ple, that is, the wall 38-ofthe staple core and outside wall 40 of the magazineare-sloped tomatewiththe slope of stapleleg 32. 1

The inner Wall of the magazine is thinner; and

may. befittedto the staplese fairly accurately.

The outer wall is of heavy; gauge metal ..making an accurate fit verydifficult to obtain. The manufacturer usually aims for a passagefiftyper cent larger than the staple thickness, but it often varies to doublethev thickness. Even. with less than double thickness, astaple-jammayjoccur inprior magazines because of the rounded section ofthe. staplewire, and. irregularities at the;stap1e ends. H

As a result ofmyangular stapleand magazine construction, the amountwhich the staple may wine t e id e 36 is severely limited. Thus,referring. to Figs..6 and 7, the -perpendicular or normal position ofthe; staple is indicated at 1 While anupwardly swung staple is.indicated at 44. 'Now it will be seen'inFig fiithatthe position- 44represents themaximum swing .of .the stapl e, for the tip end of the;staple leg ghas already reached and. engaged the, magazine wall. 46.Moreover-,in Fig. Titwillbeseenthat this rota- .15. mg of the staplesinto the machine. Or the am may not be noticed during loading, but maymani-a 4 tion of the staple is well below 45, and despite the use of avery liberal tolerance in the staple magazine. When the staple swingsonly the limited amount shown in Fig. 7 it is still under control, thatis, it will tend to be moved back to vertical position under pressure ofthe feed spring, as is illustrated} by the'successive positions in Figs.2 and-3 of the drawing, instead of tending to jam, as is illustrated inFigs. 4 and 5. Even if the staple legs were to slightly override oneanother, the continued action of the machine will correct' thecondition, because the staple legs ..will be disposed'collaterally formost of their length and-the-feed pressure will tend to right thestaplerather than to jam it. Itwilllthus be seen that by simply slopingthe snappin and by. matingly sloping the staple magazine, jamming ofstaples in the magazine may be efiectively prevented despite the use ofliberal tolerances in the machine, and despite the use of bent heavygauge sheet; metal parts for. the magazine...: i' i, a '11 The.permittedv angle s of: rotation. of thec'staple leg is determined by thelength of the leg relative-to the=clearance in thermagazinepasiwelli astheangleof the slope of thestaple'leg'. 'Theslope angle used for the-leg.emay,.of coursegvary 'greate ly. A slight anglehas some advantages,.but:decreases the permissible tolerance in.th'e'.fit-between themagazinepassagejandthe staples; A large angle increasesth -tolerance.and .decreases the'pern'rissible swingiof the;staple, but;may introduce:the disadvantage: of. reducing the strength. of the staple; leg againstbucklingowhen penetrating thick. or hard material lerecommend'an: anglebetween five? and thirty "degrees, with anangle'often'; to fifteendegrees asiprobably prefeablefor 1a satisfactory;compromise vbe. tweenthe advantages and disadvantages of more extreme angles. 3 Referringnowto Fig. 9,,I thereshow av stapling machineqhavinga conventionalstraightsided; Staple, drive channel 5,01With a drivingblade 52 matingwith-the sarne... .Thepermanent clinch: ing anvil. 5.4 is generally.Conventional, except that the clinching-slot. 5fi=is-preferablygmadedeeper and curved-t0 more gradually turn. ;the,.staple; leg 32,.thanisthe case with clinchingj-slot-58 and the perpendicular 1eg;34.,In; other words, clinching slot 58" may beconventional, butclinchingslot 55 is modified to; compensate for thefact thatthe leBlsIQms wa dly. I .,When it comesto temporary clinching. the outwardslope of the leg 32 constitutes an ad-v vantagew Thus, referringto-Figs;10cand 11,; I show an anvil having an inwardly directed, clinching. slotill] and, an. outwardly directed clinching slot;.62., Itis evident ,thatthe.,initial; outward slope oi the. Staple leg .32 ,facilitates theoutward clinching ofthesame in slot 62., In fact, theslot 62 may, ifdesired, be made shallower than the slot 60,, Thisleadsto atemporaryfasteningof the type. illustrated in Fig. 11. Some: manufacturersprefer, a temporary fastening in which the staple legs areboth turnedoutwardly. Suchan anvil may, of course, be used in lieu ofthat shown inFigs. 10 and ll,-and,in;such;case the'perpendicular. leg-.34 will be.-turned. outwardlyiin normal manner, whil th sloping leg, 32. will beturned outwardly even more; readily. 1 Both permanent .anditemporary.clinching slots may be provided onaasingle-anvll; said anvilbeing'movableinrcon'ventional manner to bring either: type. of slot.beneathii the staple driving blade. One:'arrangement is-shown in Fig. 1,in

which the anvil I4 is slidable longitudinally of the base in order tobring either of its sets of clinching slots beneath the staple drivingblade.

In Figs. 12 and 13 I illustrate a stapling machine having a modifiedstaple drive channel. In this channel the wall 64 adjacent theperpendicular staple leg 34 is a straight wall, while the wall 66adjacent the sloping leg 32 is turned inwardly at 68, thus narrowing thedrive channel at to an amount commensurate with the length of the top orbridge 36 of the staple. The staple driving blade 12 is dimensioned tofit between the walls 64 and 10, that is, it is no wider than the bridge36 of the staple. The action of this machine will be clear frominspection of the drawing. The staple remains in normal condition untilthe leg 32 reaches the inwardly sloped wall 68, whereupon the leg 32 isbent or cammed inwardly until it assumes the perpendicular relationshown in broken lines 32'. The action of the clinching anvil M will thenbe normal.

This arrangement is of advantage not only when the staples are to beclinched, but also, or perhaps even more importantly, when the staplesare to be used for tacking purposes. In common commercial parlance, astapling machine which clinches the staples is called a fastener, whilea machine which merely drives the staple legs into a solid substancesuch as wood, is termed a tacker. Some machines are made with a basewhich can be turned out of the way, so that the same machine may be usedas either a fastener or a tacker. The machine shown in. Fig. 1 is ofthis character, and when the base is swung out of the way, the staplemay be driven without any clinching action in order to secure a piece ofpaper, cardboard, fabric or the like it, to a piece of wood 18. Now whena sloping leg staple is used, the leg is preferably initiallystraightened to perpendicular relation, as shown at 3'2 in Fig. 13,before driving the same into the wood 18. After the staple has beendriven, the leg 32 tends to swing outwardly, because of its ownresilience, and this helps bind the staple against accidental removal.

While I have illustrated permanent clinching slots in Figs. 12 and 13,it will be understood that the special driving channel there shown mayalso be used with temporary clinching slots, although the special drivechannel is obviously of greater advantage for permanent clinching andfor tacking, rather than for temporary clinching. However, in all ofthese cases there is some advantage in bringing the legs to parallelcondition at the instant of driving the same, when the material to bestapled is of great thickness or unusual hardness or difficult topenetrate.

Both staple legs may be sloped, but inasmuch as the object of preventingjamming of the staple will be fulfilled while sloping a single leg, itis preferred to slope only one leg. The sloping staple leg may be slopedinwardly instead of outwardly to fulfill the desired object ofpreventing rotation of the staple about the bridge. Of course, if thesloping leg is to be cammed to perpendicular position at the instant ofdriving the same, the outwardly sloping leg is preferable to theinwardly sloping leg, because the means for camming the leg toperpendicular position is very simple, as was described in connectionwith Figs. 12 and 13. With an inwardly sloping leg the camming meanswould have to be automatically retracted as the staple driver descends.

It is believed that the construction and operation of my improved stapleand stapling machine for use with the same, as well as the importantadvantages thereof, will be apparent from the foregoing detaileddescription thereof. It will also be apparent that while I have shownand described my invention in several preferred forms, other changes andmodifications may be made in the structures disclosed, without departingfrom the spirit of the invention as sought to be defined in thefollowing claims.

I claim:

1. A stapling machine comprising a staple magazine having a staple coreand outer walls with a staple guide passage therebetween for use withstaples having a bridge and an outwardly sloping leg, said passagehaving an outwardly sloping portion for receiving an outwardly slopingstaple leg, the outer wall at said outwardly sloping portion beingspaced from said core a distance to limit the extent to which saidstaple may rotate about its bridge as an axis.

2. A stapling machine comprising a staple magazine having a staple coreand outer walls with a staple guide passage therebetween for use withstaples having a bridge and one perpendicular leg and one outwardlysloping leg, said passage having a horizontal portion for receiving thebridge of the staple, a vertical portion at one side for receiving oneleg of the staple, and an outwardly sloping portion at the other sidefor receiving the other leg of the staple, the outer wall at saidoutwardly sloping portion being spaced from said core a distance tolimit the extent to which said staple may rotate about its bridge as anaxis.

3. A stapling machine comprising a staple magazine having a staple coreand outer walls with a staple guide passage therebetween for use withstaples having a bridge and one perpendicular leg and one outwardlysloping leg, said passage having ahdrizontal portion for receiving thebridge of the staple, a vertical portion at one side for receiving oneleg of the staple, and an outwardly sloping portion at the other sidefor receiving the other leg of the staple, said outwardly slopingportion being at an angle of from 5 to 30 to the vertical, the outerwall at said outwardly sloping portion being spaced from said core adistance to limit the extent to which said staple may rotate about itsbridge as an axis.

4. A stapling machine comprising a staple magazine having inner andouter walls with a staple guide passage therebetween for use withstaples having a bridge and one perpendicular leg and one outwardlysloping leg, said passage having a horizontal portion for receiving thebridge of the staple, a vertical portion at one side for receiving oneleg of the staple, and an outwardly sloping portion at the other sidefor re-' ceiving the other leg of the staple, the inner and outer wallsof said magazine being formed out of sheet metal, the outer wall at saidoutwardly sloping portion being spaced from the inner wall thereat adistance to limit the extent to which said staple may rotate about itsbridge as an axis,

5. A stapling machine for use with staples having a bridge and anoutwardly sloping leg, said machine comprising a staple magazine havinginner and outer walls with a staple guide passage therebetween, saidpassage having an outwardly sloping portion for receiving the outwardlysloping leg Of the staple, the outer wall at said outwardly slopingportion being spaced from the inher Wall thereat a distance to limit theextent to which said staple may rotate about its bridge as an 1' axis; astaple drive, -.channel dimensioned to the width ofithe staple withitsslopinggleg and a staple driverv operable insaiddrive;channel.-- vi, i 6A stapling machine for. use with-staple having; an outwardly slopingleg, said-machine com pi'ising a staplezmagazine having inner; and outerwalls \with a staple guide passage,;therebetween; said passage having anoutwardly sloping vportion for receiving the outwardlyslopingwleg,oi;-=;the staple, the said outer and inner walls atisaid ou w slo spern be n eawee -d a to limit/the. extent .to, which said staple may rotateabout itssbridge as an axis, and. a.$1 ple, drive channel; the upper-portion Qf"; which is a dimensinned to the widthpi the slopinglegstaple put theJoweror discharge endof whichiis dimen; ed, o v h dthof th b id e of the, tapl thaupper wider .andlower narrower parts offthechannel being connected by a sloping guide or carnming surface adaptedto bend a: sloping leg to perpendicula -r position.as the staple isbeing driven, the staple driving bladeibeingdimensioned to be; receivedinv thelower narrowenportiomof the staple drive;channel.i a 5i;

A st apling; machine for usewithstaples hav T ing abridge andoneperpendioular leg and one outwardly-sloping leg, said machine comprisinga staple magazine having inner and outeriwalls withza staple guidepassage therebetween; said passage having a ehorizontal-zpolttion iorreceiving th brid ed the staple a vertical portion; at one side .forreceiving one leg-of the-.staple-,.,,and1.an outwardly tslopingnportionat theaotheriside for receiving the outwardly slopingleg of-ihesstaple,the said. outer and inner. wallsat said outwardly sloping portion beingspaced a idistance to limit the extenttowhich saidstaple-may rotateabout its bridgeaas-anaxis anda staple drive channel the'upper:portionof which; is dimensioned to the, Width of the sloping leg zstaplebut the lower "or discharge end of which is dimensionedtoythe widthofthe bridgeof the stap-le the-upper wider and lower narrower;v parts i ofthe channel being connected by a sloping guideorcamming surface adaptedto; bend thesloping leg to perpendicular positionvas -the. stapleisbeing driven, thestaiple driving 7 blade ibeing dimensioned to..- be.received in the, lower narrower portionof theistapledrive channfell A:=1 1 s. e ,LOUOBSTFELD nEEER ENoES CITED 1 The-followingreferencesarerof 'record in the file ofthispatentr v v UNITEDSTATES'PATENTS H V Number, i Date i 2,103,176 Randa1l- 1 -Dec; .21; 1937

